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| Dawn on the St. Lawrence River, Quebec Mott, 2013 |
The International Space Station has recently collected some of the most entrancing images of our planet. I love these which depict light from our electric world during the night. Examining the images, many have noted the disappearance of light in Korea north of the 38th; this latitude marks the famous North-South Korean border. As the evening lulls North Korea into dark, the rest of the developed world adjusts the night to its liking.
Armed with light bulbs and alarm clocks, we disregard the sun slipping below and above the horizon. In spite of our efforts, we are genetically indoctrinated by the sun. From plants to mouse to man, timekeeping is a pervasive component of life, apparent in the ‘circadian rhythms’ of many biological processes. Sunlight and other external cues, known as zeitgebers, entrain our physiology to these rhythms. Less than twenty years ago, scientists discovered that there was a molecular basis behind the timekeeping. This molecular basis is existent in nearly all tissues of the body; even your liver has a sense of when the sun rises!
The ability to
evaluate genes on a wide scale has revealed the pattern echoing in the
expression of our DNA. In fact, at least
10% of our genome is entrained by the circadian pattern [1]. Here is an example of the expression of thousands of genes over a 48 hour period from immune
cells. Red indicates a decrease in gene expression; Green an
increase. Notice the rise and fall for each mRNA over the course of the day;
each is timed differently, but follows a basic 24 hour phase.
It’s fascinating to think that the angular momentum of our
planet, set in place 4.6 Billion years ago, is so intrinsically tied to our DNA. Deviation
from the sun’s 24 hour pattern can prove harmful to our health. When
placed on a 28 hr schedule, man suffers a number of detrimental
health effects within ten days, including signs of a pre-diabetic state [2]. Persons on a
rotating shift schedule are at greater risk to certain cancers and affective
disorders [3].
As such, we remain swayed by the sun.
Which brings me back to the night images north of the 38th parallel. North Korea is entrained by a second sun. Every April 15th, North Korea celebrates The Day of
the Sun, a holiday that marks the birthday of the ‘eternal leader’, Kim
Il Sung. Born Kim Song-ju, he later took the name Kim Il Sung, meaning ‘become
the sun’. Sung established a tenacious
cult of personality during his 48 years of ruling; that cult has sustained for
20 yrs beyond his death. With little information from the outside world, Kim’s
cult stands as the predominant zeitgeber dictating the way of life in North
Korea*.
Footnote:
[*] For the outsider, the country is a rarefied mix of dark reports from defectors, a steady current of nuclear anxiety, and the occasional odd-glimpse of the supreme leader and his latest amusement park.This past
February, a special UN Commission wrote a 400 page investigation to
concentrate those defectors’ reports and make a case for a humanitarian crisis. With
an immediate rejection by China, the UN’s response to the accounts of
indoctrination, torture and starvation went flat. A bright side though: the
flow of information is at an all time high. Support of a grassroots organization like Liberty in North Korea can boost
that information flow and connect North Koreans to the outside world. Each year the earth and sun move another 15 cm apart; hopefully a similar progression is underway in this hidden country.
References:
[1] Hughes, A.T.L. and H.D. Piggins, Disruption
of daily rhythms in gene expression: The importance of being synchronised.
BioEssays.
[2] Scheer, F.A.J.L.,
et al., Adverse metabolic and
cardiovascular consequences
of circadian misalignment. Proceedings of the
National Academy of Sciences, 2009.
[3] Zelinski, E.L.,
S.H. Deibel, and R.J. McDonald, The
trouble with circadian
clock dysfunction: Multiple deleterious effects on the
brain and body. Neuro. &
Biobehavioral Reviews. 40(0): p. 80.
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